Long-stroke pumping mechanism



Non 5, 1929. D. l.. SHULL. 1,734,549

' LONG STROKE PUMPING MECHANISM Filed Deo. 14, 1927 3 sheets-sheet 2 Nov. 5, 1929. D. L. sHULl. 1,734,649

LONG STROKE PUMPING MEQHNISM Filed Deo. 14. 1927 s sheets-sneer 3 TTORNE Y.

Patented Nov. 5, 1929 DANIEL L. SH'ULL, OF BAKERSFIELD, CALIFORNIA, ASSIGNOR 0F ONE-FOURTH TO TUNIS SMITH, OF TAFT, CALIFORNIA LONG-STROKE PUMPING MECHANISM Application filed December 14, 1927. Serial No. 239,926.

My invent-ion relates to the oil pumping industry and particularly to a novel long stroke mechanism.

It is a common practice in the oil pumping industry to extend a pump tubing into a well, at the lower end of which tubing there is secured a pump barrel. Adapted to reciprocate in the pump barrel is a pump plunger, to which the lower end of a string of sucker rods is connected. The string of sucker rods extends upward through the pump tubing and the upper end thereof is connected to a4 walking-beam, by means of which the pump plunger is reciprocated. The stroke of the pump plunger, when using the walking-beam as a reciprocating means, is limited to about four feet.

The standard type of pump works satis factorily in wells of three thousand feet in depth or less but its operation in deeper wells is rather uncertain. This is due to the fact that the diameter of the sucker rods is limited by well conditions, and as the load is imposed thereon, on the up-stroke of the pump, the rods stretch because they are somewhat elastic. This stretch is taken up at the beginning of the down-stroke when the load is taken from the rods. The amount of the elongation of the rods is indefinite and uncertain but in very deep wells may become so great that nearly the entire four foot stroke is taken up in the stretching and releasing of the rods, allowing the pump plunger but a Very short stroke, if any. If, for example, in a deep well the rods are stretched three feet by the normal load thereon, nit is obvious that with a four foot stroke of the walk- Y ing-beam, the plunger will move only one foot and the working capacity of the pump will be only one-fourth of the full capacity. If, however, the same rods are used to operate on a nine foot stroke, the pump will operate at two-thirds its full capacity. It is therefore obvious that considerable economy can be effected by increasing the length of the stroke. Numerous attempts have been made to provide a mechanism by which such longer strokes can be obtained.

It is an object of this invention to provide a long stroke pump mechanism capable of a very long stroke.

It is another object of this invention to provide a long stroke mechanism capable of giving to the pump plunger any length of stroke desired.

It is also an object of my invention to provide a long stroke mechanism with a uniform velocity during the stroke.

It is a further object of my invention to provide a long stroke pumping mechanism using a double threaded screw.

Other objects and advantages of the invention will be made evident hereinafter.

The description of my invention will be more readily understoodwith reference to l the accompanying drawings in which- Fig. 1 is a side elevational view partly sectioned.

Fig. 2 is an end elevational View taken on the line 2-2 of Fig. 1.

Fig. 3 is a view taken on the line 3 3 of Fig. l.

Fig. 4 is a view taken on the line 4--4 of Fig. 1. Fi 5 is a view taken on the line 5-5 of Fig. 4.

Fig. 6 is a view taken on the line 6-6 of Fig. 1.

Fig. 7 is an elevational View of the rotary7 column of my invention.

Fig. 8 is a View taken on the line 8-8 of Fig. 7.

Fig. 9 is a utility view illustratin how a I counterbalance may be incorporate in my invention. l'

Referring to Fig. 9 of the drawings, the numeral 11 4represents the derrick which is placed over a well 12. Extending from the derrick 11 into the fwell 12, inside the well casing 13 thereof, is a pump tubing 14, to the lower end of which is attached a pump barrel 14. Adapted to reciprocate in the pump barrel 14 is a pump plunger 14b attached to the lower end of a string of sucker rods 15. The string of sucker rods 15 extends upward through the pump tubing 14, the upper end thereof being in the form of a polish rod 15, which extends through a stuffing box 15b attached to the upper end of the pump tubing Fig. 1 are two rotary columns 24 at the upper shown in Fig. 7.

and lower ends of which and integral and concentric with them are short shafts 37 and 38 respectively. The upper shafts 37 are mounted in bearings 39 suitably attached to the horizontal top members 20. The lower end of each of the lower shafts 38 is provided with a shoulder 39h adapted to engage a bearing 40 and a short axle 41 adapted to be mounted in the bearing 40 in a bearing box 42 of a'gear housing 43.

Each of the rotary columns 24 comprises a hollow cylindrical column to which are attached as by screws 56 track plates 57 best The track plates 57 are arcuated so that their inner surfaces have the same degree of curvature as the exterior surfaces of the cylindrical columns 55,. the outer surfaces of the track plates being curved concentric with the inner surfaces. Consecutive track plates 57 are mounted opposite each other on the cylindrical column 55 in spaced relation as best shown in Fig. 7 to form an upwardly inclined track 58 and a downwardly inclined track 59. Each of the track plates 57 has a lower and an upper track surface of the upwardly inclined track 58, represented by the numerals 60 and 61 respectively, and a lower and an upper track surface of the downwardly inclined track 59, represented by the numerals 62 and 63 respectively.

At the top and bottom of each rotary column 24 is an end track plate 84 similar to the other track plates 57 except that it extends completely around the cylindrical column 55 and comprises only an upper surface of the upwardly and downwardly inclined tracks 58 and 59. These end track plates 84 may bemade in two parts to assist in the assemblythereof.

1n each track plate 57 at the intersection of the upper tracksurface 6l of the upwardly inclined track 58 and the upper surface 63 of the downwardly inclined track 59, a notch 64 is formed. Similarly at the intersection of the lower surfaces 60 and 62 of the upwardly and downwardly inclined tracks 58 and 59 respectively, a notch 65 is formed in each track plate 57. At the intersection of the lower track surface 60 of the upwardly inclined track 58 and the upper surface 63 of the downwardly inclined track 59, a recess 66 is formed in each of the track plates 57.

Similarly at the intersection of the upfper track surface 6l, and the lower track sur ace 62 of the upwardly inclined track 58 and the downwardly inclined track 59 respectively, a recess 67, smaller than the recess 66, is formed in each of the track plates 57.

Pivotally mounted in each recess 66 by a pin 68 attached to the hollow column 55 is an arm 6 9. The arm 69 is adapted to swing on the pin 68 to its lower position, in which it engages the notch 65 of the adjoining lower track plate 57 to make continuous that poru tion of the lower surface of the u wardly inclined track 58. The arm 69 is a so adapted to be swung on the pin 68 to its upper position, in which it engages the notch 64 of the adjoining upper track late 57 to make continuous that portion o the upper track surface of the downwardly inclined track 59.

The uppermost arm 69 is provided with a dog -70 extending upward from the pivoted end of the arm as clearly shown in /Fig 7. The dog 70, formed integral with the arm 69, is adapted to be swung into a secondary recess 71 in the track plate 57. This movement of the dog 70 from the position shown in Fig. 7 into the secondary recess causes the arm 69 to move from its lower to its upper position. Similarly the lowermost arm 69 is provided with a dog 72 extending downward from the pivoted end of the arm. This dog 72 is adapted to be swung into a secondary recess 7 3 of the track plate 57, causing the arm 69 to move from its upper to its lower position.

Attached to each arm 69 is a pin 74 which extends inwardly through a slot formed in the cylindrical column 55, this slot being of a width greater than the diameter of the pin 74 to permit the arcial movement of the pin 74 as the arm 69 is swung from one position to the other. Each of the pins 74 is attached at its inner-'end to one of a pair of oppositely disposed vertical tie-bars 76, each of which is retained in slidable engagement with the inner surface of the hollow column 55 by a, guide bar 77. Each of the guide bars 77 is adapted to allow its associated tie-bar 76 some lateral movement caused by the arcial movement of the associated pins 74, as best'fshown in Fig. 6.

Suitably attached to the top of each tiebar 76, as by screws 78, is a flat spring 79 bent outwardly at its top to form a finger 80 adapted to engage the wall of an aperture 8l. in the hollow cylinder 55 when the tiebar 7 6 is in its uppermost position, as indi` cated by the dotted lines 80a of Fig. 8. YVhen in this position the spring 79 retains the tiebar 76 and associated arms 69 in their upper most position.

Pivot'ally mounted in the recess 67 of each track plate 57 by a pin 82 attached to the cylindrical column 55 is a pawl83 adapted to swing on the pin 82 ,into engagement with on, assuming its lower position from its upm per position by the force of gravity.

Associated with the polish rod a is a crossbar 21, which is adapted to vertically reciprocate the sucker rods l5. Centrally disposed in this cross-bar 2l is a hole 25 slightly greater 15 in diameter than the polish rods 15, so that the cross-bar 21 may slide upon the polish rod 15111 within the limit imposed by a shoulder 26 on the polish rod 15a above the cross bar 21, as shown in F ig. 1. At each end of the cross-bar 21 and formed integral with it -is a hub 31 and an axle 32 as clearly shown in Fig. 4. On each side of the hub 31 and in slidable engagement with it is a vertical guide 33.-

Mounted on the axle 32 is a bearing 34 which is contained in a cup shaped housing 35. In-

tegral with the housing 35 and concentric with it (the axle 32 and the bearing 34, is a roller 22 adapted to engage the faces of the tracks 58 and 59 of the rotary columns) 24. As the rotary columns 24 are rotated, the engagement of the rollers 22 with the tracks 58 and 59 causes the cross-bar 21, and associated sucker rods 15 and plunger 15b, to reciprocate.

Mounted on' the lower shaft 38 of each rotary column 24 is a worm gear 44 adapted to engage a gear 45. The gear is non-rotatably attached tov a shaft 46, which is journaled by bearings 47 within the gear housing 43.

The shaft46 extends horizontally from thev gear housing 43 substantially at right angles to the plane of the rotary columns 24 into a secondary gear housing 48 as bestshown in Fig. 2. In the secondary gear housing the shaft 46 is mounted in a bearing 49, sup' ported in a bearing box 50 formed in the gear housing 48. Non-rotatably attached to the end of the shaft 46 is a worm-gear 51 adapted to engage a gear 52. The gear 52 is nonrotatably attached to a shaft 53 journaled in bearings 54 in the housing 48. The shaft 53 extends out of the housing 48 to the secondary gear housing of the other rotary column 24, which is identical with the secondary gear housing 48. Between the two secondary gear housings 48 a drive gear 85 is non-rotatably mounted on the shaft 53. The two rotary columns 24 are associated with the shaft 53 in an identical manner.

In order to decrease the pull of the reciproi eating parts on the cross-bar 21, they may be partially counter-balanced by a weight 30 attached to the top of the polish rod 15a as by a chain 38 passing over sprockets 29 mounted on the horizontal top members 20, as clearly shown in Fig. 9.

The operation of my invention is as follows:

A prime mover suitably attached to the gear 85 being energized, the shaft 53 is caused to rotate, thereby turning by the associated wormgears 51 the shafts 46.' rlfhe shafts 46, through their associated worm-gears 44, cause the rotary columns 24 to rotate. The cross bar 21 and the arms 69 being in their lowermost position, as shown in Fig. 7, the rollers y 22 rotate in the upwardly inclined ltracks 58, causing the associated cross-bar, polish rod, sucker rods and pump plunger to rise. The upward movement of the rollers 22 and their associated mechanism continues until these rollers engage theupper surface 63 of the downwardly inclined track 59 of the end plate 84, when the downward motion of the rollers and their associated mechanism begins in the downward track 59 and continues until the rollers and their associated mechanism reach their original lowermost position.

As each roller approaches each intersection of the upwardly and downwardly inclined tracks 58 and 59, it engages the pawl 83, swinging it into an 'upward position of engagement with the upper track surface 63 of the upper adjoining track plate 57 to make continuous that portion of the upper surface of the upwardly inclined track 58. After the roller 22 has passedout of engagement with the pawl 83, the pawl falls back into its lower position of engagement with the upper track surface 60 of the lower adjoining track late 57, to 'make continuous that portion o the lower surface of the downwardly inclined track 59. As each roller 22 passes out of engagement with the uppermost arm 69, it engages the dog 70, causing the arm 69 to swing into its upper position ofI engagement with the notch 64, to render continuous th at portion of the upper surface of the downwardly inclined track 59. As the arm 69 assumes this upper position, the attached pin 74 moves upward in the slot '75 causing theattached tiebar 76 and associated arms 69 to assume their uppermost position. The tie-bar 76 and associated arms 69 are retained in this upper position by the engagement of the linger 8O of the spring 79 with the side of the aperture 81. Similarly the arms on the opposite side of each rotating column 24 have been raised by engagementl of the roller 22 with the doof 70 on the uppermost arm 69 of that side ofthe rotating column andv are similarly retained in that position so that the downwardly inclined path 59 is continuous.

When the roller 22 in its downward path reaches the lowermost arm 69, it engages the dog 72, causing it to move into the recess 73 so that the arm 69, after the passage of the roller 22, assumes its lower position as shown in Fig. 7. The movement of this lowermost arm 69 causes the attached tie-bar 76 to move the finger 80 of the spring 79.10ut of engagement with the wall of the aperture 81 into its lowermost position. The arms 69 associated with the tie-bar 76 are likewise moved into their lower position. Similarly the engagement of the roller 22 with the dog 72 of the lowermost arm 69 on the opposite side of the rotary columns 24, has caused the other tiebar 76 and associated arms 69 to assume their lowerniost position so that the lower surface of the upwardly inclined path is continuous.

As the rotary columns may be made of any length, it is apparent that I have provided a novel long stroke pump mechanism capable of giving to the pump plunger any length of stroke desired.

Since the rotarycolumns ofmyinvention are rotated at a constant speed, it should likewise be evident that I have provided a long stroke pumping mechanism in which the speed of the reciprocating parts is constant throughout the stroke.

I claim as my invention:

l. In a long stroke pumping mechanism, the combination of: a pump barrel; a pump plunger adapted to b e reciprocated in said pump barrel; a reciprocator associated with said pump plunger; a double threaded rotary screw associated with said reciprocator; gates attached to said double threaded screw at the intersection of the threads thereon, the end gates being adapted to move the others of said gates and a power means of rotating said screws.

2. In a long stroke pumping mechanism, the combination of: a pump barrel; a pump plunger adapted to be reciprocated in said pump barrel; a reciprocatorassociated with said pump plunger; engaging means associated with said reciprocator; a double threaded rotary screw associated with said engaging means; gates attached to said double threaded screw at the intersection of the threads thereon, the end gates being adapted to move the others of said gates by engagement with said engaging means; and a power means of rotating said screws.

3. A double threaded screw comprising: a column; two intersecting threads formed on said column; gates at each thread intersection; and means at the end of each threadfor changing the position of said gates.

4. A double threaded screw comprising: a column; two intersecting threads formed on said column; gates at each thread intersection, the end gates being adapted to operate the others of said gates; and a retaining means associated with said gates, said retaining means being adapted to retain said gates in one position until moved to another position by the action of one of said end gates.

5. A double tracked columncomprising: a column; two intersecting tracks formed thereon; gates at each of said track intersections, the end ones of said gates being adapted to be properly positioned by engagement with retain said primary gates substantially parallel with each other; and secondary gates atv each track intersection, each of said secondary gates being adapted to be properly positioned by engagement with an object traveling in said tracks.l

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 8th .day of December, 1927.

DANIEL L. SHULL. 

